1. Field of the Invention
The present invention relates to a process for dimerization of a lower .alpha.-olefin, using a nickel-containing catalyst.
2. Description of the Related Art
Dimers of lower .alpha.-olefins such as ethylene, propylene, butene, etc. are useful as important raw materials in the production of agricultural chemicals, pharmaceuticals, medicines, perfumes, cosmetics and other chemicals or as monomers of polymers. It is known that the dimers are prepared by dimerizing the lower .alpha.-olefin in the presence of a nickel-containing catalyst system. Known nickel-containing catalyst systems for dimerization of the lower .alpha.-olefins are, for example, a catalyst system comprising a nickel compound, a trialkylaluminum, a phosphorous compound and a halogenated phenol (cf. Japanese Patent Kokai Publication No. 39004/1979), a catalyst system comprising a nickel compound, a trialkylaluminum, a phosphorous compound, a halogenated phenol and water (cf. Japanese Patent Kokai Publication No. 167932/1982), a catalyst system comprising a nickel compound, a bisdialkylaluminoxane, a phosphorous compound and a halogenated phenol (cf. Japanese Patent Kokai Publication No. 169433/1982) and a catalyst system comprising a nickel compound, a trialkylaluminum, a phosphorous compound and a fluorinated isopropyl alcohol (cf. Japanese Patent Kokai Publication Nos. 158225/1987 and 221335/1989).